Detection of the Common Carcinogen Benzene in Sunscreen Products
A recent study by Valisure, an analytical laboratory that performs independent chemical analysis assays of pharmaceutical-related products, found detectable levels of benzene in several brands and batches of sunscreen and after-after-sun care products (Dermatology Times, 2021). Valisure is now urging the FDA to recall product batches, including gels, sprays, and lotions, that contain detectable levels of benzene because of potential carcinogenic concerns. Sunscreen is considered a drug by the United States (U.S.) Food and Drug Administration (FDA), since it contains one or more active ingredients intended to prevent disease (e.g., skin cancer) (FDA, 2017a).
Benzene is classified as a human carcinogen by many regulatory agencies because of the increased incidence of blood cancers, such as acute myeloid leukemia (AML) and chronic myeloid leukemia (CML), following exposure (IARC, 2018; CDC, 2018). The FDA currently regulates benzene in drug products a “Class 1 solvent,” meaning that the intentional introduction of benzene into drugs or consumer products is not permitted. An exception is provided, however, if the introduction of benzene is unavoidable for manufacture of a drug with a “significant therapeutic advance,” in which case the specified limit is 2 ppm (FDA, 2017b).
Valisure’s testing revealed detectable levels (>0.02 ppm) of benzene in 27% of samples tested (78/294) (Valisure, 2021). Specifically, 26 samples contained 0.1-2.0 ppm of benzene, while 14 samples mostly consisting of spray sunscreen formulations had benzene levels greater than the FDA-specified limit of 2 ppm (range: 2.78 – 6.26 ppm). Benzene was found in both chemical and mineral-based sunscreen formulations, although significant variability from batch to batch was noted even among the same brand. According to Valisure, the benzene contamination likely occurred during the product’s production, rather than from degradation of its active ingredients (e.g., avobenzone, oxybenzone, octisalate, octinoxate, homosalate, and octocylene).
Everyday exposures to benzene can occur from a variety of sources, including tobacco smoke, gas stations, motor vehicle exhaust, glues, paints, furniture wax, and detergents (CDC, 2018). While benzene is a known toxic compound, the risk of adverse health effects from benzene, including increased cancer risk, depends on the exposure concentration, route (e.g., dermal, inhalation), and length of time exposed (e.g., short term; lifetime). An exposure and risk assessment that takes these factors into account should be conducted to determine whether using these products may lead to potential adverse health effects.
Cardno ChemRisk scientists have extensive experience analyzing data obtained from independent sources (e.g., testing laboratories, published literature), using this data to perform risk assessments, and providing recommendations pertaining to human and environmental health. We have evaluated the available carcinogenicity data in benzene-exposed cohorts such as those exposed to complex mixtures, including gasoline and oil refinery air (Keenan et al., 2010; Kreider et al., 2010). Further, Cardno ChemRisk scientists have extensive experience performing risk assessments of consumer products such as sunscreen (Novick et al., 2013), and others containing potentially carcinogenic compounds (Towle et al., 2017). Please contact Dr. Ernest Fung or Dr. Andy Monnot for more information regarding Cardno ChemRisk’s capabilities.